As the Russian-backed Syrian army threatens to liberate Aleppo, potentially determining the outcome of five years of civil war, Saudi Arabia is challenging the US to lead a ground invasion that could escalate into an historic battle for a country that has been fought over for centuries.

President Barack Obama has so far maintained he will not send U.S. ground forces into Syria, beyond a few hundred special forces. But the Saudis, the U.A.E. and Bahrain, driven by fierce regional ambitions, said last week they are ready to invade if the U.S. will lead, pressuring Obama to decide if he's willing to lose Syria to Russia and Iran.

Vice President Joe Biden in Istanbul last month hinted at a possible Obama change in position when he said if U.N.-led peace talks in Geneva failed, the United States was prepared for a "military solution" in Syria.

The U.N.'s unconditional peace talks collapsed on Wednesday when the Saudi-led opposition made a condition that Russia cease its aerial campaign. A day later Saudi Arabia said it was ready to invade Syria with the U.S. It was revealed the same day that Turkey is building up its forces at the Syrian border.

Defense Secretary Ashton Carter welcomed the Saudi declaration though he made no commitment about U.S. ground forces. But Saudi Brigadier General Ahmed Asseri told al-Arabiya TV that a decision could be made to intervene at a NATO summit in Brussels next week. Carter said it would be on the agenda.

Saudi officials told CNN that war games with 150,000 troops from the kingdom, Qatar, Jordan, the UAE, Morocco, Sudan and Egypt would be held in March. And on Feb. 1 Lt. Gen. Sean Mac Farland said the U.S. would need more troops in Syria.

Turkey has begun preparations for an invasion of Syria, according to the Russian Defense Ministry. On Thursday ministry spokesman Igor Konashenkov said:"We have good reasons to believe that Turkey is actively preparing for a military invasion of a sovereign state - the Syrian Arab Republic. We're detecting more and more signs of Turkish armed forces being engaged in covert preparations for direct military actions in Syria." The U.N. and the State Department had no comment. But this intelligence was supported by a sound of alarm from Turkey's main opposition party, the Republican People's Party (CHP).

Turkey, which has restarted its war against Kurdish PKK guerillas inside Turkey, is determined to crush the emergence of an independent Kurdish state inside Syria as well. Turkish strongman Recep Tayyip Erdogan stopped the Syrian Kurds from attending the aborted Geneva talks.

A Turkish invasion would appear poised to attack the Syrian Kurdish PYD party, which is allied with the PKK. The Syrian (and Iraqi) Kurds, with the Syrian army, are the main ground forces fighting the Islamic State. Turkey is pretending to fight ISIS, all the while actually supporting its quest to overthrow Assad, also a Turkish goal.

Of course Biden, Erdogan, Carter and the Saudis are all saying a ground invasion would fight ISIS. But their war against ISIS has been half-hearted at best and they share ISIS' same enemy: Syrian President Bashar al-Assad. If the U.S. were serious about fighting ISIS it would have at least considered a proposal by Russia to join a coalition as the U.S. did against the Nazis.

The Prize of Aleppo

The excuse of the Geneva collapse is a ruse. There was little optimism the talks would succeed. And they were sabotaged by the Saudi opposition though the West blamed Russia. The real reason for the coming showdown in Syria is the success of Russia's military intervention in defense of the Syrian government against the Islamic State and other extremist groups. Many of these groups are supported by Saudi Arabia, Turkey and the United States in pursuit of overthrowing Assad.

These three nations are all weighing a ground invasion of Syria just as, by no coincidence, the Syrian Arab Army with Russian air cover is pushing to liberate perhaps the greatest prize in the Syrian civil war--Aleppo, the country's commercial capital. The Russians and Syrians have already cut off Turkey's supply lines to rebels in the city. Taking Aleppo would be a major turning point in the war.

The neocons in Washington could not likely stand by and watch Russia win in Syria. At the very least they may well want U.S. troops on the ground to meet the Russians at a modern-day Elbe and influence the outcome.

But things could go wrong in a war in which the U.S. and Russia are not allies, as they were in World War II. Despite this, the U.S. and its allies see Syria as important enough to risk confrontation with Russia, with all that implies. It is not at all clear though what the U.S. interests are in Syria to take such a risk.

From the outset of Russia's intervention the U.S. and its allies have wanted Moscow out of the Syrian theater. They seem to be only waiting for the right opportunity. That opportunity may be now--forced by events.

Former U.S. national security adviser and current Obama adviser Zbigniew Brzezinski said last October in the Financial Times that, "The Russian naval and air presences in Syria are vulnerable, isolated geographically from their homeland. They could be 'disarmed' if they persist in provoking the U.S."

Turkey's downing in November of a Russian warplane that veered 17 seconds into Turkish territory appeared to be very much a provocation to draw Russia into a conflict to allow NATO to drive Moscow out of Syrian skies. But Russia was too smart for that and instead imposed sanctions on Turkey, while urging Russian tourists not to visit the country, which has hurt the Turkish economy.

A Battleground of Empires

As a fertile crossroad between Asia and Africa backed by desert, Syrian territory has been fought over for centuries. Pharaoh Ramses II defeated the Hittites at the Battle of Kadesh near Lake Homs in 1247 BCE. The Persians conquered Syria in 538 BCE. Alexander the Great took it 200 years later and the Romans grabbed Syria in 64 BCE.

Islam defeated the Byzantine Empire there at the Battle of Yarmuk in 636. In one of the first Shia-Sunni battles, Ali failed to defeat Muawiyah in 657 at Siffin along the Euphrates near the Iraq-Syria border. Damascus became the seat of the Caliphate until a coup in 750 moved it to Baghdad.

Waves of Crusaders next invaded Syria beginning in 1098. Egyptian Mamluks took the country in 1250 and the Ottoman Empire was born in 1516 at its victory at Marj Dabik, 44 kilometers north of Aleppo--about where Turkish supplies are now being cut off. It may be the spot where Erdogan's neo-Ottoman dreams die.

France double-crossed the Arabs and gained control of Syria in 1922 after the Ottoman collapse. The Nazis were pushed out in the 1941 Battle of Damascus.

We may be now looking at an epic war with similar historical significance. All these previous battles, as momentous as they were, were regional in nature.

What are potentially facing a war that goes beyond the Soviet-U.S. proxy wars of the Cold War era, and beyond the proxy war that has so far taken place in the five-year Syrian civil war. Russia is already present in Syria. The entry of the United States and its allies would risk a direct confrontation between the two largest nuclear powers on earth.

Joe Lauria has been a independent journalist covering international affairs and the Middle East for more than 20 years. A former Wall Street Journal United Nations correspondent, Mr. Lauria has been an investigative reporter for The Sunday Times (more...)

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